US2362645A - Machine for sewing shoes - Google Patents

Description

Nov. 14, 1944. B. 'r. LEVEQUE 2,

MACHINE FOR SEWING SHOES Filed Dec. 23, 1940 3 Sheets-Sheet 1 I NOV. 14, 1944. 1' LEVEQUE MACHINE FOR SEWING SHOES 3 Sheets-Sheet 2 Filed Dec. 25, 1940 "LIZ Q22 9 ma m Nov. 14, 1944. B. T. LEVEQUE 2,362,645

MACHINE FOR SEWING SHOES Filed Dec. 23, 1940 5 Sheets-Sheet 3 Patented Nov. 14, 1944 UNITED STATES PATENT OFFICE MACHINE FOR SEWING SHOES Bernard T. Leveque, Wenham, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application December 23, 1940, Serial No. 371,263

15 Claims.

illustrated as being embodied in a chainstitchv shoe sewing machine similar in many respects to that disclosed in U. S. Letters Patent of the present inventor No. 1,738,778, of December 10, 1929.

One object of the present invention is to improve previously known sewing machines and to provide a novel form of machine which will insert a seam of tighter and more durable nature than heretofore considered possible.

The machine disclosed in the inventors patent above identified is a hook needle chainstitch shoe sewing machine of the McKay type having an angular rotatable shoe supporting horn. Thread is laid in the book of the needle by' a rotary needle threading whirl located at the tip of the born, the needle being so arranged that it draws a loop of thread laid in its hook by the whirl through the work and sets a. previously formed stitch. The loop of thread is retained on the shank of the needle during the next work penetrating stroke and the succeeding loop of thread is drawn through the previous loop to form each chainstitch. Due to the lack of means for providing a suflicient amount of thread between the last formed stitch and the whirl before looping the needle in this machine, a certain amount of thread sliding movement inevitably occurs in the hook of the needle as the needle withdraws from the work. Sliding movement in the hook of the needle necessitates the use of a substantially larger needle than is required if no sliding movement takes place and consequently a larger perforation is made in the work than can ordinarily be'filled completely by the thread carried by the needle.

Attempts heretofore have been made in-machines of this type to sew with more than one thread in order to fill compactly each needle perforation in the material operated upon. These attempts have not met with success due to improperly controlled methods and means for handling the threads and forming the needle perforations. Accordingly, further objects of the invention are to improve the construction and arrangement of a hook needle sewing machine so that more than one thread may be successfully employed in forming a continuous scam in which the needle perforations in the work will be filled with threads more compactly than heretofore and in which the threads are located in a uniform and predetermined relationship with respect to each other and with respect to the materials operated upon. Thus, a definite and desirable control may be exercised over the type of seam to be inserted. v

An outstanding characteristic of a chainstitch seam is in its'easy removability by a pull on the leading end of thread in the seam. Various means have been utilized to prevent easy removal of such a seam so as to render it capable of being employed in place of a lockstitch seam. According to a further object of the present invention, a simple and eifective machine is provided for inserting a chainstitch seam which is not easily removable by a pull on the leading end of thread and in which the thread of each stitch is tightly wedged within the needle perforations in the material operated upon, not only by filling each perforation compactly with thread, but by additional wedging effects not heretofore obtainable in a chainstitch seam.

With these and other objects in view, the features of the invention consist in the provision of stitch forming devices for a sewing machine which include a looper and a needle having a shank formed with a plurality of thread receiving hooks. Preferably, the barbs of the needle hooks are located one above the other at the same side of the needle shank. The looper, according to this feature of the invention, is arranged to lay one thread in each of the needle hooks and in the illustrated form of this feature, means for laying the threads in the hooks comprises a rotary whirl having spaced thread guiding eyes. In order to facilitate laying the thread in the hooks of the needles, as hereinafter described, the outlets of the thread eyes are disposed at different levels.

According to the present invention, the position of the threads during the formation of a seam are controlled uniformly to cause the threads to be drawn into the material operated upon in a regular predetermined relationship. One of the principal factors which determines the relationship taken by the threads in a twothread seam has been found to be the shape of the perforation in the material through which.

the line of the seam, when the lengths of thread extending between theperforations are drawn tight. one of the threads will be drawn into one of the incision crevices, preventing dislocation by tension on the other threaxh By so doing, a relationship in the threads is maintained in which one of the threads is pressed beneath the other to embed the first thread more deeply than otherwise would occur into the surface of the material operated upon. A seam of this nature frequently is desirable where hard, stiff material is being sewn. Where softer material is being sewn, perforations are formed with incisions extending crosswise of the seam, so that when the lengths of thread extending between successive perforations are drawn tight, they will be carried away from the crevices formed by the incisions. As a result, the lengths of thread between perforations will lie side by side. Such an arrangement of threads causes a more even distribution of pressure between the threads and the work and a flatter seam than in the case where one thread length is pressed beneath the other.

While many of the features of the invention are applicable to sewing machines generally, certain of the features ar useful only with a machine of the McKay type having an angular rotatable shoe supporting horn and particularly so, as regards certain features relating to mechanism for rotating the whirl and to an improved whirl driving gear construction at the tip of the horn.

These and other features of the invention, and the advantages attained thereby,'will be understood more fully from the following description taken in connection with the accompanying drawings which illustrate the several features as embodied in a chainstitch McKay shoe sewing machine.

In the drawings, Fig. 1 is a view in front elevation of a portion of a shoe sewing machine embodying the features of the present invention; Fig. 2 is a view in side elevation, looking towards the left, of some of the parts illustrated in Fig. 1; Fig. 3 is a vertical sectional view, on an enlarged scale, taken along the line 3-4 of Fig. 2; Fig. 4 is a detail view, taken in section along the line 44 of Fig. 3; Fig. 5 is aplan view of a part of the whirl rotatin mechanism in the machine; Fig. 6 is a sectional plan view, taken along the line 6-6 of Fig. 1; Fig. 7 is a sectional view taken along the line l'| of Fig. 3; Fig. 8 is a detail view illustrating in front elevation, on an enlarged scale, the manner in'which the threads are handled by the needle and whirl just before the needle penetrates the work to form a new stitch in a seam; Fig. 9 is a similar view showing the positions of the parts after the needle has entered the work; Fig. 10 is a similar view showing the position of the whirl after laying the threads in the hooks of the needle; Fig. 11 is another view of the same parts indicating their positions as the threaded needle is withdrawing from the work; Figs. 12 to 15 inclusive are plan views taken in section along the line l2-i2 of Fig. 8, showing the positions of the needle and whirl corresponding to the respective positions illustrated in Figs. 8 to 11 inclusive; Fig. 16 is a vertical sectional view of thetip of the horn; Fig. 1'7 is a sectional view of the whirl at the tip of the horn, on an enlarged scale, taken along the line i|l| of Fig. 13; Fig. 18 is a view of a seam formed by the machine of Fig. l illustrating the positions of the threads taken in the individual stitches, the work being shown in section along the seam line; Fig. 19 is a view taken along the surface of the work illustrating the enchained loop portion of the seam of Fig. 18; Fig. 20 is a similar view, taken along the under side of the work, a portion having been cut away and shown in section, as viewedalong th line 20-20 of Fig. 18; Fig. 21 is a sectional view of a seam in the preferred form; Fig. 22 is a plan view of the enchained loops in the preferred form of scam; Fig. 23 is a view of the preferred seam on the opposite side of the work from that shown in Fig. 22, a portion being broken away and shown in section alon the line 23-23 of Fig. 21; Fig. 24 is a view in side elevation, on an enlarged scale, of the shank of a. needle employed to insert the seam illustrated in Fig. 18; Fig. 25 is a view of the needle shank illustrated in Fig. 24 showing the profile of the work penetrating point, looking from behind the needle hooks; Fig. 26 is an end view of the point of the needle shown in Fig. 24; Fig. 2'7 is a view of a shank of a needle employed to form the seam illustrated in Fig. 22; Fig. 28 is a view of the needle shank of Fig. 27, showing the profile of the work penetrating point, looking from behind the needle hooks; and Fig. 29 is an end view of the point of the needle shown in Fig. 2'7.

The seam inserted by the machine of the present invention comprises sets of loops in parallel threads drawn through successive perforations in heavy compressible work material, the loops of one set being enchained with each previously formed set and after enchaining the sets, a tension is applied to draw the threads of certain of the loops somewhat below the surface of the material. Due to the manner of handling the threads and to the shape of the perforation formed in the material operated upon, the threads of successive stitches assume uniform positions and are arranged with relation to the perforations, in the manner illustrated in the drawings, to prevent easy withdrawal so that the results compare favorably with a two-thread lockstitch seam. At the same time, many of the desirable characteristics of a chainstitch seam are retained, such as the ease with which the stitches are set, as compared with th stitches of a lockstitch seam.

Referring more particularly to Figs. 18 to 23 of the drawings, a chainstitch seam is illustrated which, instead of employing a single thread, is composed of two parallel threads 2 and 4, loops 6 and 8 of which are drawn through the perforations in the materials operated upon and passed through each set of the loops 6, 8 drawn through the previous perforation. As illustrated, these threads are of such size that wax or other means is employed to facilitate drawing them through the materials and to assist, after becoming solidified, in holding them more firmly within the perforations. The materials with which Waxed threads are employed ordinarily include heavy compressible substances such as sole leather, harness leather, soft woods, and even manufactured fibrous materials. The present materials operated upon consist of a shoe insole l0 and an outsole or upper i2 as the case may be, such as are sewn in a well-known McKay type of shoe. In

- sewing this type of shoe, it is desirable to draw engagement between the threads.

to the bight of the other, resulting in substantial cutting or sawing action at the point of inter- However. as against a chainstitch seam, the thread ordinarily is not locked so securely in the material of the work as in a lockstitch.

In order to insert a chainstitch seam in a manner to compare favorably in looking character with a lockstitch seam, so that a .chainstitch seam may be employed to advantage insome instances where a lockstitch seam only has been effective previously, two parallel threads are employed in the chainstitch seam, according to the present invention, and are arranged in a manner to cause them to be gripped within the perforations of the work material more tightly than with previous chainstitch seams. By using two threads in the seam illustrated, the perforations in the work material are not only filled more compactly with strands of thread but, as will be more fully described hereinafter, the bight portion of one loop of thread is forced into each perforation by the bight portion of the other thread, thus causing the strands of thread already in the perforation to be gripped still more securely. The position of the bights of thread in the stitches illustrated in Figs. 18 and 21 is crosswise to the strands passing through the perforation, the bight of each loop 8 being forced into a perforation to a position below the level I of the outer surface by the pressure against the big'ht portion of each loop 6 exerted by the strands of thread in the succeeding set of loops while lying along the surface of the material operated upon. As a result, strands of thread passing through each perforation are squeezed into the form of a kink 9, offering substantial resistance to withdrawal of the thread even when heavy tensions are applied to the leading ends in the seam. In each type of stitch illustrated, the bight of a loop 6 is pressed against the bight of a loop 8 when the threads in the completely formed stitch are tensioned to set the stitch. This occurs when the tensions on the last set of loops 6, 8 at the right are transferred through the last perforation and along the lengths of thread at the lower side of the work extending between perforations and back through the second to last perforation, which tensions are carried along the second to last set of loops 6, 8.

The forces of these loops in being drawn tight act to press the bights of the third to last set of loops through which they pass into the second to last perforation with awedging action in the manner stated. Since this wedging action occurs always during application of the final stitch setting tension on the second to last set of loops, the materials operated upon are drawn tightly together with a uniform pressure, as in the usual single thread chainstitch seam.

In the form of the seam illustrated in Figs. 18, 19 and 20, the threads are drawn through the perforations in the material in such relationship that the diametrically arranged strands, filling each perforation, are connected with the ends of the same loop. This arrangement of the strands of thread in each perforation differs from that in the seam illustrated in Figs. 21, 22 and 23, in which the side by side strands of thread in each half of a perforation divided substantially lengthwise of the seam are connected to the ends of the same loop.

The arrangement of the strands of thread in a perforation is regulated by a number of factors, the principal one or which is the shape of the perforation, as originally formed. The shape of perforation conducive to the location of the strands of thread in the seam of Figs. 18, 19 and 20 is illustrated at H in Fig, 20. This perforation is formed with an incision extending in the direction of the seam line, which incision has its sides spread apart sufficiently to provide space for the strands of thread being drawn through the perforation. When the perforation is opened up into the shape illustrated to receive the threads, the ends of the incision produce crevices IS in alignment with the seam line. These crevices have a tendency to hold the strands of thread which originally are located in them and prevent their displacement during thread movement through the perforation. The crevices in the perforation, therefore, tend to cause the strands of thread, particularly at the side of the work opposite the enchained loops, to assume a relationship conforming with the shape of the perforation which is more or less in diamond form. No practical amount of tension in the threads will upset this relationship because the threads will merely embed themselves deeper into the material of the work. As a result of the relationship between the strands of thread in a perforation of this shape and of the tensions imparted to the threads while setting each stitch,

the thread 4 will be located uniformly in the crevices l6 and the thread 2 will take a position in each perforation such that the ends of the connected loop are diametrically opposite to each other.

The relation between the strands of thread in a perforation, disclosed in Figs. 18, 19 and 20, causes the lengths of thread extending between successive perforations at the side of the work opposite the enchained loops (Fig, 20) to lie in contact one above the other and to embed themselves into the surface of the work material. The action of the outer length of thread 2 on the inner length of thread 4 between perforations is to force the inner thread more firmly against the material tending to embed it more deeply. The appearance of the seam at the side opposite from the enchained loops, therefore, particularly when relatively short stitches are employed, closely resembles that ofa single thread seam, the outer thread 2 obscuring the inner thread 4. Thus, the seam of Figs. 18, 19 and 20 is useful where it is desired to simulate a single thread seam while retaining the advantages of a two-thread seam.

With the seam of Figs. 21, 22 and 23, each perforation I8 is formed with an incision extending substantially crosswise of the seam line providing crevices 20 disposed in alignment at right angles to the crevices l6 of Figs. 18, 19 and 20. With the alignment of the crevices 20 crosswise of the seam line, the threads, when tensioned, are easily carried out of the crevices. If the tensions in the threads are made equal, the lengths of thread extending between perforations opposite the enchained loops will lie side by side in parallel relation along the surface of the work, as best shown in Fig. 23. A seam inserted in this form is useful in distributing the pressures exer-ted on the work and in providing a flatter seam than that of Figs. 18, 19 and 20. Also, if threads of different colors or shades are used, an unusual ornamental effect results, as indicated by the shaded and unshaded lengths of thread in Fig. 23.

To insert uniform seams of the type described, a McKay shoe sewing machine having an angular rotatable shoe supporting horn 2| is provided which is of the same construction and mode of opposite the hooks to be made stiffer and stronger. than where a single hook of similar thread carry ing capacity is employed. The means for laying the threads in the hooks of the needle includes a rotary whirl 32 mounted at the upper end of the horn 2 I, together with driving mechanism for the whirl. Instead of a needle opening and a single thread eye in the whirl, as in the patented machine, the present whirl has two thread eyes 33 and 34 spaced angularly about the needle opening, the outlets of which eyes are disposed at different levels lengthwise of the whirl rotational axis (see Fig. 17). To this end, the thread eye 33 extends through the full thickness of the whirl and the other thread eye 34 extends only partway through the thickness of the whirl. The re maining part of the whirl thickness is cut away to form a recess 36 providing space for the thread extending from the thread eye 34 as the threads 2 and 4 are being laid in the respective hooks of the needle. The outlet of the thread eye 33 being higher than that of the thread eye 34, causes its thread 2 to be laid in the needle hook 28, whereas the thread eye 34 having its outlet lower, acts to lay the thread 4 in the lower thread hook 38.

In laying the threads 2 and 4 in the hooks of the needle, as illustrated in Figs. 8 to 15 inclusive, the threads are carried successively around the needle in the direction of the arrow in Fig. 13, starting from the position of Fig. 9 and stopping with Figs. 10 and 14. As soon as the threads are laid in the respective hooks in the needle, the nee- .dle begins to withdraw from the needle perforation and the loops formed by the needle are carried to the upper surface of the work and through the previously formed loops which have been retained on the needle during the work penetrating stroke thereof. It will be noted that these previously formed loops of thread 6, 8 are in the positions of those in Figs. 18 and 19, and are held loosely around the needle, shielded from engagement with the rising needle hooks by a cast-off 38 operated in the manner disclosed in the patent. The cast-oil in the illustrated machine is provided at its lower end with a needle engaging surface of suflicient length to shield both hooks of the needle. Due to the manner of laying the thread in the needle hooks, the threads 2 and 4 cross each other as they are being drawn through the work, but during continued upward movement of the needle, the crossed sections of thread are wholly withdrawn from the work, as illustrated in Fig. 8. During the needle withdrawing movement, the whirl does not continue its rotation but moves in a direction opposite to its needle threading movement. From the position of Fig. 14, the whirl moves in the direction of the arrow to the partly withdrawn position of Fig. 11. When the needle has completely withdrawn, as indicated in Fig. 8, the whirl has rotated more than 180 (Fig. 12) From the position of Fig. 12, it continues in the same direction, as indicated by the arrow, Fig. 12, until the needle has again penetrated the work, as shown in Figs. 9 and 13. During the needle withdrawing movement, the previously formed loops 6, 8 of thread, through which the needle projects, are tightened to provide thread for one side of each new loop formed by the needle as the threaded hooks move through the material of the work. The stitch setting tensions on the threads are exerted principally by the needle as it reaches the upper end of its withdrawing movement and after the needle has withdrawn, the work is fed the length of a stitch by a feed point 48 (see Fig. 1) so that the threads are drawn slightly to one side of the needle perforation. In tensioning the threads, the last formed stitch is set but the formed loops of this stitch are not forced into the work until the next succeeding stitch is formed and set. When the next succeeding stitch is set, the loops previously carried by the needle are tightened while lying along the surface of the work, thus exerting a downward pressure against the loops of the previously formed stitch with which theyare enchained, as

, previously explained.

position of Fig. 15 when the needle reaches its In order to cut perforations with incision crevices uniformly aligned in the proper direction in the present machine, the point of the needle is provided with knife edges extending either in the same direction in which the thread hooks open or crosswise to the opening of the thread hooks, according to the type of scam desired. Referring to Figs. 24, 25 and 26, the shank of the needle provided with the hooks 28 and 38 has barbs located one above the other at the same side of the needle shank. The knife edges on this needle are indicated at 42 extending from the extreme tip of the point upwardly along the sides of the needle and merging with the rounded circumferential shank surface. One of the cutting edges is directly beneath'and in alignment with the barbs of the needle. Since the normal position of the needle in the needle clamp of the machine disclosed is indicated in Fig. 8, the cutting edges of the needle pont will form perforations having incision crevices in alignment with the seam similar to that shown in Fig. 20.

A needle for forming perforations having incision crevices aligned in a direction extending crosswise of the'seam line with the present machine is illustrated in Figs. 27, 28 and 29. The shank 44 of this needle is formed with hooks 46 and 48, the barbs of which are one above the other at the same side of the shank corresponding to the books 28, 38 of Fig. 24 and at the point there are knife edges 50. The knife edges 50 of this needle extend crosswise to the direction in which the hooks 46, 48 open and at either side of the barbs of the hooks, the forward portion of the needle from the extreme tip to the barb of the lower hook 48 to the point is formed with a flattened surface 52 acting to spread the cut sides of a perforation and the opposite side of the needle has a face 54, the margin of which forms the cutting edges 50. A needle having this form of shank, when employed in the illustrated machine, will cut a perforation having incision crevices disposed crosswise to the seam line, as indicated in Fig. 23.

The construction of a gear train for driving the needle threading whirl at the tip of the horn 21 in the present type of machine has heretofore presented difliculties both in the design of the gear train itself and in the manner of rotatably mounting the individual gears of the train. Due to the necessity of providing a horn tip with suitably small externaldimensions, it has been the practice to cut driving gear teeth for the whirl which are not of standard design, such as is known to be conducive to durability and quietness of operation. In the driving gear train for a whirl with this type of horn, a pair of bevel gears are required connecting an inclined drive shaft, indicated at 56, in Figs.--.1 and 16 of the drawings, to the whirl. Due to lack of space, it has been the practice heretofore to provide one bevel gear on the upper end of the inclined drive shaft 56 having teeth which are of larger size than the best design requires, the teeth also being more widely spaced than usual for the diameter of gear employed. To reduce the'outside diameter of this gear still further, in compliance with available space requirements, previous whirl driving mechanisms have been constructed with a two-to-one driving ratio between the whirl and the driving shaft, the driving shaft rotating twice for each single rotation of the whirl.

In order to render possible the use of a bevel gear at the upper end of the inclined drive shaft 56, which will be less subject to wear and will operate more quietly than heretofore, while at the same time permitting use of a one-to-one ratio between the inclined shaft 56 and the whirl in the present machine, the bevel gear at the end of the inclined shaft acts to drive the whirl 32 through a plurality of intermediate gears 58 and 68. The intermediate gears 58 and 68 bridge the distance between the whirl and a location in the horn where suitable space is available to receive a bevel gear, indicated at 62, of full size for a, one-to-one driving ratio and with teeth out according to accepted design in'shape and spacing. Teeth of the gear 62 mesh with correspondingly' shaped teeth on a bevel gear portion 64 of the gear 58. The teeth on the gear 58 have a slight angular cut corresponding in shape to teeth on the gear 58, which in turn mesh with teeth on the whirl 32.

The whirl is rotatably mounted at the end of a block 66 secured to the main body portion of the horn 2| and a cap piece 68 holds the whirl in place in a manner explained in inventors prior U. S. Letters Patent No. 1,786,624 of Dece'mber 38, 1930. The gear 68 is supported for rotation on a screw 18 acting with a screw 12 to hold the cap piece 68 on the block 66.

To support the gear 58, the cap piece carries a stud 14 passing through the gear and the gear is held from movement along the stud I4 by a shoulder portion I6 on the block 66, which shoulder portion enters a groove 18 formed in the gear 58, By this construction, proper mesh between the teeth of gears 62, 64 is insured.

The driving mechanism for the whirl 32 includes the inclined drive shaft 56 rotatable in a bearing 88 at the upper end of the horn. The inclined shaft 56 is squared at its lower end and is connected by means of a coupling block 82 (see Figs. 1 to 7 inclusive) with the upper end of a flexible shaft 84, the lower end of which is clamped in a chuck 86 carried'by a block 88 on a vertical actuating shaft 98. The actuating shaft 98 rotates in hearings in a bracket 92 comprising a part of the machine frame, which bearings are located substantially in alignment with the rotary axis of the horn 2|. The horn is clamped to the upper end of a vertical rotary spindle 84 as is usual with this type of machine, which spindle has suitable bearings, one being indicated at 96, in the main frame of the machine. To control the position of the flexible shaft 64, the shaft is enclosed in a sheath 98. The upper end of the sheath is clamped in a stationary socket by a set screw I88, the head of which is exposed on the outer surface of the horn. The lower end of the sheath is secured by a split block I82 made fast to the lower end of the horn spindle 94.

In order to align the needle threading whirl with the needle in a McKay type sewing machine, it is the practice to loosen a series of cap screws indicated at I84, which clamp the horn to the rotary spindle 94 and slide the horn along the top surface of the spindle until suitable adjustable adjustment is obtained. With the use of a flexible shaft, the lower end of which is secured to a vertical actuating shaft rotatable in the frame of the machine and the upper end of which is connected to a. drive shaft within the horn spindle, no special means is necessary to take care of improper alignment of the driving connections between the drive shaft and whirl ordinarily resulting from movement of the horn along the surface of the spindle when adjusting the position of the whirl.

To prevent breakage of the parts in case'the whirl or its driving connections become jammed in thehom with thread or otherwise held from rotating during sewing operations, the block 88 for the chuck 86 has a slip connection with the drive shaft 88. The slip connection consists of a ball I86 fitting a perforation in the side of a socket portion on the block and a suitable indentation for receiving the ball partially in the drive shaft. Surrounding the socket portion of the block is a semi-circular leaf spring I88 (see Fig. 4) one end of which is made fast to the block 88 and the other end presses against the ball I86 to hold it within the indentation of the drive shaft.

The driving mechanism for rotating the whirl and drive shaft first in one direction and then in the other includes a pinion M8 on the drive shaft and a gear segment forming one arm of a bell crank H2 rotatable on a stud II4 secured in the bracket 82. The other arm of the bell crank is connected by means of a ball-and-socket joint to one end of a pitman H6, the other end of which is similarly connected to a crank H8. The crank H8 is 'made fast to the forward end of a horizontal shaft I28 corresponding to the horizontal whirl driving shaft II8 of inventors Patent No. 1,738,778.

To insure that the threads forming the present seam will be subject to equal tensions regardless of tension adjustments, the present machine is equipped with a spring-pressed tension plate I22 of known construction between which and a flat seat on the machine frame the sewing threads pass. The plate I22 is supported on a threaded stud I24 extending from the machine frame and a thumb nut I26 on the stud acts through a suitable tension spring to press the plate against the machine frame. To equalize the pressure of the plate on the threads, one thread is located at one side of the stud I24 and the other thread at the other side. Thus, regardless of the adjustment of the thumb nut I26, the drag exerted by the plate is kept equal on both threads. From the tension, the thread passes over a 'pair of pulleys I28 downwardly into a wax pot (not shown), and upwardly through a stripper I30 over a pair of pulleys I32 and into the horn spindle. To prevent twisting of one thread on the other, due to rotation of the hbrn, the horn is limited in its rotation to not more than 360. For this purpose, the under surface of the horn spindle has a projecting screw I34, the head of which engages a right angle stop plate I36 secured to the machine frame.

The nature and scope of the invention having been indicated and constructions embodying the several features of the invention having been specifically described what is claimed is:

-1. A sewing machine for operating upon sole leather or similar compressible material having, in combination, stitch forming devices including a looper and a reciprocating needle having a shank provided with a plurality of thread receiving hooks arranged to receive a separate strand of thread in each hook during each reciprocation.

2. A sewing machine for operating upon sole leather or similar compressible material having,

in combination, stitch forming devices including a looper and a needle having a shank provided with a plurality of thread receiving hooks, the barbs of which are located one above the other at the same side of the shank of the needle.

3. A sewing machine for operating upon sole leather or similar compressible material having in combination, stitch forming devices including a needle having a shank provided with a plurality of thread receiving hooks, and means for laying a separate thread in each hook of the needle.

4. A sewing machine for operating upon sole leather or similar compressible material having,

. in combination, stitch forming devices including a needle having a shank provided with a plurality of thread receiving hooks, and a rotary needle threading whirl having spaced thread eyes for laying a separate thread in each hook of the needle.

5. A sewing machine for operating upon sole leather or similar compressible material having,

' in combination, stitch forming devices including a needle having a shank provided with a plurality of thread receiving hooks, and a rotary needle threading whirl having spaced thread eyes, the outlets of which are disposed at different levels along the axis of whirl rotation.

6. A sewing machine for operating upon sole leather or similar compressible material having, in combination, stitch forming devices including a needle having a shank provided with a plurality of thread receiving hooks, and a rotary needle threading whirl having angularly spaced thread eyes for laying a separate thread successively in the hooks of the needle.

'7. A sewing machine for operating upon sole leather or similar compressible material having, in combination, stitch forming devices including a looper and a needle havinga shank provided with a plurality of thread receiving hooks, and a work penetrating point formed with knife edges disposed to cut an incision extending in the same'direction in which the thread receiving hooks open and to cause one of the threads, when tensioned, to be drawn into a crevice of the incision as the threaded needle withdraws from the work.

8. A sewing machine for operating upon sole leather or similar compressible material having, in combination, stitch forming devices including a looper and a needle having a shank provided with a plurality of thread receiving hooks, and a work penetrating point formed with knife edges disposed to out an incision extending crosswise to the direction in which the thread receiv ing hooks open and to cause the threads, when tensioned, to lie side by side along the surface of the work as the threaded needle is drawn through the work.

9. A shoe sewing machine having, in combination, stitch forming devices including a needle having a shank provided with a plurality of thread receiving hooks, means for laying a separate thread in each hook of the needle, and a cast-01f for covering the hooks'as the needle withdraws from the work and for uncovering the hooks during the succeeding work penetrating stroke of the needle.

10. A shoe sewing machine of the McKay type having, in combination, stitch forming devices including a straight hook needle, an angular rotatable shoe supporting horn, a rotary needle threading whirl at the tip of the horn, a drive shaft in thehorn inclined to the work supporting surface of the horn for rotating the whirl, a bevel gear on the drive shaft, and a plurality of intermediate gears between the whirl and the bevel gear on the drive shaft for transmitting the motion of the drive shaft to the whirl, the gear most remote from the whirl having bevel teeth meshing with the teeth of the bevel gear on the drive shaft.

11. A shoe sewing machine of the McKay type having, in combination, stitch forming devices including a straight hook needle, an angular rotatable shoe supporting horn, a rotary needle threading whirl at the tip of the horn, a drive shaft in the horn inclined to the work supporting surface of the horn for rotating the whirl, a bevel gear on the drive shaft, a plurality of intermediate gears between the whirl and the bevel gear on the drive shaft for transmitting the motion of the drive shaft to the whirl, the gear most remote from the whirl having bevel teeth mashing with the teeth of the bevel gear on the drive shaft, a cap piece covering the whirl, and a stud on the cap piece for supporting one of the intermediate gears. 1

12. A shoe sewing machine of the McKay type having, in combination, stitch forming devices including a straight hook needle, an angular rotatable shoe supporting horn, a rotary needle threading whirl at the tip of the horn, a drive shaft in the horn inclined to the work supporting surface of the horn for rotating the whirl, a bevel gear on the drive shaft, a plurality of intermediate gears between the whirl and the bevel gear on the drive shaft for transmitting the motion of the drive shaft to the whirl, the gear most remote from the whirl having bevel teeth meshing with the teeth of the bevel gear on the drive shaft, a cap piece covering the whirl, a stud on the cap piece for supporting one of the intermediate gears, and a shoulder on the horn for holding the intermediate gear on said stud.

13. A shoe sewing machine of the McKay type having, in combination, stitch forming devices including a straight hook needle, an angular rotatable shoe supporting horn, a rotary needle threading whirl at the tip of the horn, a drive shaft in the horn inclined to the work supporting surface of the horn for rotating the whirl, a main frame in which the stitch forming devices are mounted, a bearing for the horn in the frame, a flexible shaft connected at one end to the inclined shaft in the horn, and an actuating shaft to which the other end of the flex-- ible shaft is secured rotatable in the frame.

14. A shoe sewing machine of the McKay type devices are mounted, a bearing for the horn in the frame, a flexible shaft connected at one end to the inclined shaft in the horn, an actuating shaft rotatable in the frame, and a yielding slip 15 connection comprising a block rotatable on the actuating shaft and a chuck carried by the block for securing the flexible shaft to the actuating shaft.

15. A sewing machine for operating upon sole leather or similar compressible material having, in combination, stitch forming devices including a looper with two separate thread eyes and a needle arranged to receive threads passing through both thread eyes of the looper and a shread tension device engaging the threads to prevent unequal drag on the threads passing to the stitch forming devices.

"BERNARD T. LEVEQUE.

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